Jet pump

ABSTRACT

A jet pump including a housing having a central longitudinal bore and at least one longitudinal return bore, the central bore is in fluid communication with the return bore. A nozzle is disposed in the central bore in fluid communication with a mixing section. A chamber is formed within the central bore proximate the nozzle and the mixing section. A production inlet port is formed radially through the housing between the chamber and the exterior of the housing. The top of the housing is adapted for connecting a conduit for providing the motive or power fluid to the central bore and the carried nozzle and for returning the mixed motive and production fluid from the return bore to the surface. The jet pump may further include a check valve mechanism positioned in the production inlet ports. The check valve mechanism allowing fluid flow through the port from the exterior of the housing into the central bore and substantially blocking flow through the port directed from the central bore to the exterior of the housing.

FIELD OF THE INVENTION

The present invention relates to jet pumps.

BACKGROUND

Jet pumps in general include a power fluid conduit and a produced fluidreturn line connected from the surface to the pump. Pressurized powerfluid is forced by a pump at the surface down through the jet pumpdrawing a production fluid into the pump and intermixing with the powerfluid. The intermixed power and production fluid are then returned tothe surface through the return line. In a common installation, the jetpump is run into a wellbore on a tubing for de-watering hydrocarbonbearing wells and/or producing hydrocarbons.

Typically these prior art jet pumps draw the production fluid through astanding valve positioned at the base of the pump. These bottom draw jetpumps often fail due to sludge or particulate in the fluid.Additionally, many of these prior art jet pumps include torturousproduction and mixed fluid paths and multiple valve assembliesincreasing points of failures and increasing the cost of constructingand repairing the pumps. Further, many of these prior art pumps aredifficult to start up as the flow of motive fluid is stabilized drawingproduction fluid into the pump.

Therefore, it is a desire to provide an improved jet pump that addressesshortcomings of prior art jet pumps. It is a still further desire toprovide a jet pump having radial production inlet ports.

SUMMARY OF THE INVENTION

Accordingly, a jet pump is provided. The jet pump including a housinghaving a central longitudinal bore and at least one longitudinal returnbore, the central bore is in fluid communication with the return bore. Anozzle is disposed in the central bore in fluid communication with amixing section. A chamber is formed within the central bore proximatethe nozzle and the mixing section. A production inlet port is formedradially through the housing between the chamber and the exterior of thehousing. The top of the housing is adapted for connecting a conduit forproviding the motive or power fluid to the central bore and the carriednozzle and for returning the mixed motive and production fluid from thereturn bore to the surface. The central bore and the return bores are influid connection proximate the bottom of the housing. The fluidconnection may be provided by a bull plug further closing the bottom endof the housing from fluid communication with the exterior of thehousing.

It may further be desired for the jet pump to include a check valvemechanism positioned in the production inlet ports. The check valvemechanism allowing fluid flow through the port from the exterior of thehousing into the central bore and substantially blocking flow throughthe port directed from the central bore to the exterior of the housing.

The foregoing has outlined the features and technical advantages of thepresent invention in order that the detailed description of theinvention that follows may be better understood. Additional features andadvantages of the invention will be described hereinafter which form thesubject of the claims of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features and aspects of the present inventionwill be best understood with reference to the following detaileddescription of a specific embodiment of the invention, when read inconjunction with the accompanying drawings, wherein:

FIG. 1 is a cross-sectional view of an embodiment of a jet pump assemblyof the present invention,

FIG. 2 is a cross sectional view of the housing along the line 2-2 ofFIG. 1; and

FIG. 3 is a cross-sectional side view of an embodiment of a housing ofthe present invention.

DETAILED DESCRIPTION

Refer now to the drawings wherein depicted elements are not necessarilyshown to scale and wherein like or similar elements are designated bythe same reference numeral through the several views.

As used herein, the terms “up” and “down”; “upper” and “lower”, andother like terms indicating relative positions to a given point orelement are utilized to more clearly describe some elements of theembodiments of the invention. Commonly, these terms relate to areference point as the surface from which drilling operations areinitiated as being the top point and the total depth of the well beingthe lowest point.

FIG. 1 is a cross-sectional view of a jet pump assembly of the presentinvention generally denoted by the numeral 10. Jet pump assembly 10includes a housing 12 having a central bore 14 and a plurality of mixedfluid return bores 16 formed substantially parallel to the longitudinalaxis of housing 12. Housing 10 may be constructed of any materialsuitable for the fluids produced and well conditions. For example, thehousing may be constructed of steel, stainless steel, polypropylene,polyvinyl chloride, acrylic, or polytetrafluorethylene.

Housing 12 further includes at least one production inlet port 18 influid communication between central bore 14 and the exterior of housing12. Production inlet port 18 is formed radially through housing 12 andis not located at the bottom of housing 12.

Housing 10 includes a first end 20 adapted for connecting to a motivefluid conduit 11 and a mixed fluid return line conduit 13, such as astring of tubing. The second end 22 of housing 22 is adapted forcarrying a bull plug 24 for creating fluid communication between returnbores 16 and central bore 14.

Jet pump 10 further includes a nozzle assembly 26 and a mixing tubeassembly 28 disposed within central bore 14 of housing 12. Nozzleassembly 26 includes a power fluid channel 30 connected to a nozzle 32.Nozzle assembly 26 may be pumped to the surface for repair orreplacement by reversing fluid flow through pump 10.

Mixing tube assembly 28 includes a mixing section 34 and a mixed fluidconduit 36. Mixing tube assembly 28 is disposed in central bore 14 withmixing section 34 position below and in fluid communication with nozzle32.

A vacuum chamber 38 is formed within central bore 14 proximate nozzle 32and mixing section 34. Production inlet ports 18 are formed radiallythrough housing 12 proximate chamber 38. Fluid communication betweenchamber 38 and the exterior of housing 12 is provided through ports 18.As power or motive fluid 40 is discharged from nozzle 32 into mixingsection 34, a low pressure or vacuum is created in chamber 38. Formationor production fluid 42 is drawn through production inlet ports 18 intomixing section 34 and mixes with motive fluid 40 to form a mixed fluidstream 44.

As shown in FIG. 1, production inlet ports 18 are shown as beingsubstantially parallel to central bore 14. However, it should berecognized that ports 18 may be at any desired angle in relation tocentral bore 14. Production ports 18 are substantially cylindrical boresand in the present embodiment include a check valve mechanism 46connected therein. Radial check valve mechanisms 46 may be fixedly orremovably connected within port 18 as described further in relation toFIGS. 2 and 3.

FIG. 2 is a cross-sectional view of housing 12 of the present inventionalong line 2-2 of FIG. 1. The Figure illustrates a plurality of mixedfluid return bores 16 formed longitudinally through housing 12. The sizeand number of return bores 16 are determined as a design choice.

Check valve mechanism 46 may take numerous forms. For example, radialcheck valve mechanism 46 includes at least a check valve member 58operable within port 18 to substantially prevent fluid flow from bore 14through port 18 to the exterior of housing 12. As shown, in theillustrated embodiments check valve mechanism 18 is a ball, however, itmay comprise other elements such as, but not limited to, flappers. In apreferred embodiment, ball 58 is moveable within port 18 betweeninterior port end 18 a, proximate bore 14, and exterior port end 18 b,open to the exterior of housing 12. Desirably, interior port end 18 a iseither adapted, or includes a blocking member, to prevent ball 58 frompassing through without sealing fluid flow. Exterior port end 18 b isadapted to prevent ball 58 from passing there through and is adapted forbeing sealed to prevent fluid flow toward the exterior of housing 12.

In the illustrated embodiments, the check valve mechanism is a checkvalve insert 46 shown removably disposed within production inlet port18. Check valve inserts 46 include a substantially circular tube 48having a first open end 50 and a second open seating end 52. Tube 48includes external threads 54 for threadably engaging threads 56 formedby production inlet port 18. In this manner, check valve insert 46 canbe removed or replaced when desired. In an embodiment not illustrated,check valve mechanism 46 may comprise a single open seating cap, similarto seating end 52 entrapping ball 58 within port 18. In a still furtherembodiment, a check valve insert 46 or similar check valve assembly maybe fixedly connected within port 18 by welding or adhesive or otherattaching mechanisms known in the art.

A check ball 58 is movably disposed within tube 48 between first openend 50 and second seating end 52. First open end 50 may have a smallerinside diameter than the outside diameter of ball 58 to prevent ball 58from passing there through. In the embodiment illustrated, a blockingmechanism 60, illustrated as a pin, is connected to tubing 48 proximatefirst open end 50 to prevent ball 58 from passing through first open end50 and from sealing first open end 50. Second sealing end 52 includes aseating surface 62 adapted for mating with ball 58 to substantiallyblock fluid flowing from central bore 14 through port 18 to the exteriorof housing 12. As is shown, and will be understood in the description ofthe operation of the system, first open end 50 is oriented towardcentral bore 14 and second seating end 52 is oriented toward theexterior of housing 12.

FIG. 3 is cross-sectional side view of an embodiment of housing 12 ofthe present invention. This Figure illustrates a production inlet port18 without a check valve 46 installed. Port 18 further illustrates theinternal threads 56 adapted to mate with threads 54 of tube 48. Asshould be understood in operation of the current invention, it may bedesired from time to time to operate jet pump 10 without check valveinserts 46.

With reference to FIGS. 1 through 3, an embodiment of a method ofproducing a fluid and operating jet pump 10 of the present invention isprovided. Jet pump 10 is disposed within a fluid to be produced.Commonly, jet pump 10 will be disposed in a wellbore for producing waterand/or hydrocarbons. Jet pump 10 comprises a housing having a centrallongitudinal bore 14 and at least one longitudinal return bore 16. Aproduction inlet port 18 is formed radially through housing 12 in fluidcommunication between central bore 14 and the exterior of housing 12.Disposed within central bore 14 is a nozzle 32 and a mixing section 34positioned proximate each other and production inlet port 18 to define avacuum chamber 38. A bull plug or fluid diverter 24 is connected to thesecond or bottom end 22 of housing 12 to fluidly connect mixing section34 through central bore 14 to return bores 16. A motive fluid conduit 11is connected to the first or top end 20 of housing 12 in fluidcommunication with central bore 14 and nozzle 32. A produced fluidconduit 13 is connected to first end 20 of housing 12 in fluidcommunication with return bores 16.

In operation, a motive or power fluid 40 is pumped through motive fluidconduit 11, nozzle assembly 26 and out of nozzle 32 into mixing section34 of mixing tube assembly 28. When motive fluid 40 is discharged fromnozzle 32 into mixing section 34, a low-pressure or vacuum is created invacuum chamber 38 drawing production fluid 42 through production inletbore 18 into chamber 38 and mixing section 34.

With check valve mechanism 46 disposed in production inlet port 18, ball58 is unseated permitting production fluid 42 to enter housing 12. Checkvalve 46 provides a mechanism to aide in a quicker and more economicalmeans of start-up. When motive fluid 40 is initially pumped into pump10, ball 58 will seat against seating end 52 allowing the flow of motivefluid 40 to stabilize and a low-pressure to be created in chamber 38.

Production fluid 42 mixes with motive fluid 40 in mixing section 34 andmixed fluid conduit 36. The mixed fluid stream 44 is rerouted at bullplug 24 into return bores 16 and into produced fluid conduit 13.

As can be seen from the disclosure of the present invention, an improvedjet pump 10 is provided. The present invention eliminates intake of theproduction or formation fluid from the bottom of the pump eliminatingstanding valves and the associated limitations and failures. Forexample, in bottom intake jet pumps solids are often encountered whichcan plug the production intake, typically a standing valve, causing afailure in sealing fluid from passing out of the pump and preventing theintake of fluid. The addition of a radial check valve mechanismfacilitates a quicker, more efficient and economical start-up of the jetpump.

From the foregoing detailed description of specific embodiments of theinvention, it should be apparent that a jet pump that is novel has beendisclosed. Although specific embodiments of the invention have beendisclosed herein in some detail, this has been done solely for thepurposes of describing various features and aspects of the invention,and is not intended to be limiting with respect to the scope of theinvention. It is contemplated that various substitutions, alterations,and/or modifications, including, but not limited to, thoseimplementation variations which may have been suggested herein, may bemade to the disclosed embodiments without departing from the spirit andscope of the invention as defined by the appended claims which follow.

1. A jet pump comprising: a housing having a central longitudinal boreand at least one longitudinal return bore, the central bore in fluidcommunication with the return bore; a nozzle disposed in the centralbore in fluid communication with a mixing section; a chamber formedwithin the central bore proximate the nozzle and the mixing section; anda production inlet port formed radially through the housing between thechamber and the exterior of the housing.
 2. The jet pump of claim 1,wherein a bottom end of the housing is closed to fluid communication tothe exterior of the housing.
 3. The jet pump of claim 1, furtherincluding: a check valve mechanism disposed within the radial productioninlet port; and wherein the check valve mechanism substantially blocksfluid flow through the production inlet port from the central bore tothe exterior of the housing and permits fluid flow through theproduction inlet port from exterior of the housing to the central bore.4. The jet pump of claim 3, wherein the check valve mechanism comprisesa ball.
 5. The jet pump of claim 3, wherein the check valve mechanismcomprises: a ball movably disposed within the radial production inletport between an interior bore end and an exterior bore end; and aseating end connected proximate the exterior bore end having a seatingsurface adapted for mating with the ball.
 6. The jet pump of claim 5,further including a blocking member disposed within the radialproduction inlet port proximate the interior bore end adapted to preventthe ball from passing through the interior bore end.
 7. The jet pump ofclaim 5, wherein the seating end is removably connected proximate theexterior bore end.
 8. The jet pump of claim 3, wherein a bottom end ofthe housing is closed to fluid communication to the exterior of thehousing.
 9. The jet pump of claim 4, wherein a bottom end of the housingis closed to fluid communication to the exterior of the housing.
 10. Thejet pump of claim 5, wherein a bottom end of the housing is closed tofluid communication to the exterior of the housing.
 11. The jet pump ofclaim 6, wherein a bottom end of the housing is closed to fluidcommunication to the exterior of the housing.
 12. The jet pump of claim7, wherein a bottom end of the housing is closed to fluid communicationto the exterior of the housing.
 13. The jet pump of claim 1, wherein thehousing does not comprise a standing valve.
 14. A jet pump comprising: ahousing having a central longitudinal bore and at least one longitudinalreturn bore, the central bore in fluid communication with the returnbore; a nozzle disposed in the central bore in fluid communication witha mixing section; a chamber formed within the central bore proximate thenozzle and the mixing section; a production inlet port formed radiallythrough the housing between the chamber and the exterior of the housing;and a check valve insert disposed within the radial production inletport, the check valve insert comprising a ball movably disposed in atube between a first open end and a second seating end; wherein thecheck valve insert substantially blocks fluid flow through theproduction inlet port from the central bore to the exterior of thehousing and permits fluid flow through the production inlet port fromexterior of the housing to the central bore.
 15. The jet pump of claim14, wherein a bottom end of the housing is closed to fluid communicationto the exterior of the housing.
 16. The jet pump of claim 14, whereinthe check valve insert is fixedly connected within the radial productioninlet bore.
 17. The jet pump of claim 15, wherein the check valve insertis fixedly connected within the radial production inlet bore.
 18. Thejet pump of claim 14, wherein the check valve insert is removablyconnected within the radial production inlet bore.
 19. The jet pump ofclaim 15, wherein the check valve insert is removably connected withinthe radial production inlet bore.
 20. The jet pump of claim 14, whereinthe housing does not comprise a standing valve.